US carriers like Verizon have started testing Voice over LTE (VoLTE) as a replacement for old-fashioned circuit-switched voice, but South Korean carrier SK Telecom is set to be first in the world to launch a VoLTE service. The company will introduce its new "HD Voice" service tomorrow, and begin selling Galaxy S III LTE phones with the feature, Korea IT Times reports. Additionally, the carrier will provide an update enabling the HD Voice service for existing Galaxy S III devices "within the month." The IT Times reports that the carrier also plans to embed HD Voice in "most" of its LTE phones in the future. The jury seems to still be out on the value of VoLTE, but its definitely something carriers around the world are taking seriously: Verizon and MetroPCS plan national deployments, and it's likely that every LTE carrier will eventually deploy it when standards like GSM and UMTS are retired in the future.
Update: It turns out that MetroPCS beat SK Telecom to the punch by a single day, taking the title of "first carrier to offer VoLTE service." So close, yet so far.